Temple Gates Games
Dominion is an official online implementation of Dominion, produced by Temple Gates Games. It is available on multiple platforms, including Steam, and various mobile app stores. The game is in early access.
Features
All released cards are implemented on the TGG client.
Games can be played against one or more of three difficulties of AI, or other humans; 2-4 player games are supported.
The AI has been touted as a headlining feature of the client, claiming to be taught via neural networks, and receiving some press upon its announcement.
Card gallery can be used to customize the kingdom. You can also ban cards there. Cards banned state will be maintained for future games. In multiplayer, atm the creator determines the bans.
Cross platform play SteamPC + Android + iOS.
Asynchronous play so you can play a game over the course of a month.
Pass-and-Play mode so you can play a game with your friends using just one phone.
Tutorial to help new players learn the base game or different expansions.
Cost
The base game is free to download and play.
Payment is one-time per expansion, rather than the subscription model that Dominion Online uses.
Purchases can be shared across platforms by entering an email in Profile->Online Account->Add Email.
The developers are honoring purchases of expansions made through previous platforms (Goko and Making Fun), though those clients only ever implemented up to Adventures.
Gameplay
For unranked games the expansions used depend on what the table host owns and selects. Anyone who joins in does not need to own the same expansions.
For ranked games the system is TBD.
Currently the client is only available in English and Japanese.
Links
Temple Gates Games Discord server